ABSTRACT
Photocatalytic membranes are a promising technology for water and wastewater treatment. Towards circular economy, extending the lifetime of reverse osmosis (RO) membranes for as long as possible is extremely important, due to the great amount of RO modules discarded every year around the world. Therefore, in the present study, photocatalytic membranes made of recycled post-lifespan RO membrane (polyamide thin-film composite), TiO2 nanoparticles and graphene oxide are used in the treatment tertiary-treated domestic wastewater to remove trace organic compounds (TrOCs). The inclusion of dopamine throughout the surface modification process enhanced the stability of the membranes to be used as long as 10 months of operation. We investigated TrOCs removal by the membrane itself and in combination with UV-C and visible light by LED. The best results were obtained with integrated membrane UV-C system at pH 9, with considerable reductions of diclofenac (92%) and antipyrine (87%). Changes in effluent pH demonstrated an improvement in the attenuation of TrOCs concentration at higher pHs. By modifying membranes with nanocomposites, an increase in membrane hydrophilicity (4° contact angle reduction) was demonstrated. The effect of the lamp position on the light fluence that reaches the membrane was assessed, and greater values were found in the middle of the membrane, providing parameters for process optimization (0.29 ± 0.10 mW cm-2 at the center of the membrane and 0.07 ± 0.03 mW cm-2 at the right and left extremities). Photocatalytic recycled TiO2-GO membranes have shown great performance to remove TrOCs and extend membrane lifespan, as sustainable technology to treat wastewater.
Subject(s)
Graphite , Membranes, Artificial , Titanium , Waste Disposal, Fluid , Wastewater , Water Pollutants, Chemical , Water Purification , Titanium/chemistry , Water Pollutants, Chemical/chemistry , Wastewater/chemistry , Graphite/chemistry , Waste Disposal, Fluid/methods , Catalysis , Water Purification/methods , Organic Chemicals/chemistry , Recycling/methods , Ultraviolet Rays , OsmosisABSTRACT
Oleogels have been explored as fat substitutes due to their healthier composition compared to trans and saturated fats, also presenting interesting technological perspectives. The aim of this study was to investigate the compositional perspective of multicomponent oleogels. Structuring ability of lecithin (LEC) (20 or 90 wt% of phosphatidylcholine - PC) combined with glycerol monostearate (GMS), sorbitan monostearate (SMS) or sucrose monostearate (SAC) in sunflower oil was evaluated from oleogels properties. The thermal and rheological properties, microstructure and stability of the oleogels were affected by the difference in the chemical composition of LEC and the ratio between LEC and different surfactants. Interestingly, low-phosphatidylcholine LEC (L20) performed better, although systems formed with reduced amounts of LEC tended to be softer (LEC-GMS) and present high oil holding capacity (LEC-SMS). The mixtures of LEC and monostearate-based surfactants showed different behaviors, depending on the surfactant polar head. In LEC-GMS systems, LEC hindered the self-assembly of GMS in sunflower oil, compromising mechanical properties and increasing oil release. When combined with SMS, LEC acted as a crystal habit modifier of SMS, forming a more homogeneous microstructure and producing stronger oleogels with greater oil binding capacity. However, above the threshold concentration, LEC prevented SMS self-assembly, resulting in a weaker gel. A positive interaction was found in LEC-SAC formulations in specific ratios, since SAC cannot act as a single oleogelator. Results show the impact of solubility balance played by LEC and fatty-acid derivatives surfactant when combined and used as oleogelators. This knowledge can contribute to a rational perspective in the preparation and modulation of the properties of edible oleogels.
Subject(s)
Lecithins , Organic Chemicals , Rheology , Sunflower Oil , Surface-Active Agents , Lecithins/chemistry , Organic Chemicals/chemistry , Sunflower Oil/chemistry , Surface-Active Agents/chemistry , Hexoses/chemistry , Fat Substitutes/chemistry , Glycerides/chemistry , Sucrose/chemistryABSTRACT
We used bench-scale tests and mathematical modeling to explore chemical oxygen demand (COD) removal rates in a moving-bed biofilm reactor (MBBR) for winery wastewater treatment, using either urea or nitrate as a nitrogen source. With urea addition, the COD removal fluxes ranged from 34 to 45 gCOD/m2-d. However, when nitrate was added, fluxes increased up to 65 gCOD/m2-d, twice the amount reported for aerobic biofilms for winery wastewater treatment. A one-dimensional biofilm model, calibrated with data from respirometric tests, accurately captured the experimental results. Both experimental and modelling results suggest that nitrate significantly increased MBBR capacity by stimulating COD oxidation in the deeper, oxygen-limited regions of the biofilm. Our research suggests that the addition of nitrate, or other energetic and broadly used electron acceptors, may provide a cost-effective means of covering peak COD loads in biofilm processes for winery or another industrial wastewater treatment.
Subject(s)
Waste Disposal, Fluid , Water Purification , Waste Disposal, Fluid/methods , Nitrates , Biofilms , Bioreactors , Organic Chemicals , Water Purification/methods , Nitrogen , Urea , DenitrificationABSTRACT
One challenge of the citrus industry is the treatment and disposal of its effluents due to their high toxicity, substantial organic load, and consequent resistance to conventional biotechnological processes. This study introduces a novel approach, using electrochemical oxidation with a boron-doped diamond anode to efficiently remove organic compounds from biodegraded pulp wash (treated using the fungus Pleurotus sajor-caju.) The findings reveal that employing a current density of 20 mA cm-2 achieves notable results, including a 44.1% reduction in color, a 70.0% decrease in chemical oxygen demand, an 88.0% reduction in turbidity, and an impressive 99.7% removal of total organic carbon (TOC) after 6 h of electrolysis. The energy consumption was estimated at 2.93 kWh g-1 of removed TOC. This sequential biological-electrochemical procedure not only significantly reduced the mortality rate (85%) of Danio rerio embryos but also reduced the incidence of morphologically altered parameters. Regarding acute toxicity (LC50) of the residue, the process demonstrated a mortality reduction of 6.97% for D. rerio and a 40.88% lethality decrease for Lactuca sativa seeds. The substantial reduction in toxicity and organic load observed in this study highlights the potential applicability of combined biological and electrochemical treatments for real agroindustrial residues or their effluents.
Subject(s)
Diamond , Water Pollutants, Chemical , Diamond/chemistry , Water Pollutants, Chemical/analysis , Electrolysis/methods , Organic Chemicals , Electrodes , Oxidation-ReductionABSTRACT
BACKGROUND: Solid fats are critical to obtaining a wide range of food texture and quality characteristics, but their consumption is strongly associated with higher cardiovascular disease risks. Structuring unsaturated oils with natural waxes into oleogels (OG) is an innovative solution to develop fat mimics with a healthier profile. RESULTS: Soy wax (SW), beeswax (BW) and carnauba wax (CW), have been used in binary mixtures of waxes, aiming to understand their interactions and influence on OG quality properties and microstructural characteristics. In the present study, OGs were produced using binary wax mixtures and analyzed for texture, color, smoke point, microstructure, Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Wax combinations led to antagonistic (mixtures with SW) and synergistic interactions (BW/CW) based on their mechanical properties. At the microstructural level BW/CW blends showed a reduction in crystal size and with a more compact structure. XRD and FTIR spectra revealed a packing of orthorhombic perpendicular subcell for most OGs, whereas SW produced samples with an arrangement with ß' crystals, characteristic of edible solid fats. Additionally, when compared to commercial beef fat, BW/CW mixtures showed similar quality attributes indicating that they could act as fat mimic. CONCLUSION: The combined analysis of microstructure, spectroscopic and mechanical properties enhanced the understanding of how the nature of the interactions between waxes and lipid phases impact in the final quality of the structured oils. The study's insights indicate that binary wax combinations can efficiently replace solid fats, offering healthier alternatives at the same time as preserving desired sensory characteristics. © 2024 Society of Chemical Industry.
Subject(s)
Organic Chemicals , Waxes , Waxes/chemistry , Organic Chemicals/chemistry , Spectroscopy, Fourier Transform Infrared , X-Ray DiffractionABSTRACT
This study is a bibliometric analysis and literature review on the use of oleogels (OGs), hydrogels (HGs) and hybrid gels (HYGs) in chocolate, compounds and spreads with the aim of reducing the saturated fat in these products. The articles were selected by analyzing titles, keywords and abstracts in the Web of Science (WoS), Scopus and Google Scholar databases. Supplementary documents were obtained from government sources, including patent registrations. The theoretical and practical aspects were critically analyzed, highlighting the main points of agreement and disagreement between the authors. The results revealed a lack of regulations and official guidelines that widely allow the use of OGs, HGs and HYGs in chocolate confectionery products. The type and characteristics of raw materials affect the properties of products. Replacing cocoa butter (CB) with OGs, HGs or HYGs also affects texture, melting point and behavior, and nutritional aspects. These substitutions can result in products with better sensory acceptance and health benefits, such as reducing saturated fat and promoting cardiovascular health. However, it is important to find the ideal combination and proportions of components to obtain the desired properties in the final products.
Subject(s)
Cacao , Chocolate , Chocolate/analysis , Hydrogels , Fatty Acids/analysis , Organic ChemicalsABSTRACT
The effect of the cold-set and heat-set gelling mechanism of whey protein isolate on bigel production was assessed. For this purpose, hydrogel phase was produced with whey protein isolated (10 % w/v) and for oleogel sunflower oil and glycerol monostearate (7.5 % w/v) were used. Bigels were produced by hot emulsification of different hydrogel:oleogel ratios (from 90:10 up to 10:90). For cold-set bigels (CSB) NaCl (200 mM) was added to the aqueous phase prior to the emulsification and the emulsion was cooled to promote the 3D network formation. On the other hand, heat-set bigels (HSB) were produced by heating the emulsion (80 °C, 60 min). Bigels were evaluated through microscopy, FTIR, thermal and texture analyzes. Results showed that depending on the hydrogel:oleogel ratio and gelling mechanism different structures organization were obtained. CSB were more organized, showing that the rate of gelation was the mechanism responsible for the structure. However, for HSB the heat treatment destabilized the emulsion and disorganized structures were observed for high oleogel content. FTIR corroborates the visual observation and showed that the arrangement was purely physical. In addition, the structural arrangement led to different mechanical properties. In general, HSB produced gels with rubber-like behavior, higher elasticity modulus and the presence of a breaking point. In contrast, CSB behaves as squeezing gel, with no breaking point and lower values of elasticity modulus. Moreover, for O/W bigels the dispersed oleogel particles disrupted the WPI network decreasing the gel strength in comparison to pure hydrogels. However, for systems where oleogel was the continuous phase, the gel strength was recovered due to the metastable and dynamic character of these systems. Thus, results showed that the gelling mechanism of the protein exerted an effect on the physical properties of bigels. In addition, the mechanical properties also can be modulated according to the bigel composition, allowing its application in products with different sensorial characteristics.
Subject(s)
Hydrogels , Organic Chemicals , Whey Proteins , Emulsions , Hydrogels/chemistry , Organic Chemicals/chemistryABSTRACT
Epidermolysis bullosa (EB) is a group of rare, difficult-to-treat, inherited multisystem diseases affecting epithelial integrity. Impaired wound healing is central and can lead to serious clinical complications, deformities, and symptoms with a devastating impact on quality of life (QoL). Dressing changes and wound care are central to the management of EB. Recently Oleogel-S10 (also known as birch bark extract or birch triterpenes) was approved in Europe and the UK for treating EB wounds. This approval was based on data from the EASE phase 3 study, which demonstrated Oleogel-S10 accelerated wound healing, reduced total wound burden, and decreased the frequency of dressing changes in patients with EB. A retrospective analysis of medical records was conducted for up to 24 months in 13 patients with EB treated with Oleogel-S10 through an early access programme in Colombia. Effectiveness was assessed by measuring body surface area percentage (BSAP) and total body wound burden (EBDASI). Tolerability and safety were monitored throughout. This is the first report to evaluate the effectiveness of Oleogel-S10 in clinical practice. The results showed a reduction in percentage of BSA affected, from a mean of 27.3% at baseline to 10.4% at 24-month follow-up, despite treatment interruptions. A reduction in EBDASI skin activity score of - 16.2 (24 months) together with a reduced skin damage index score of - 15.4 (18 months) was also observed. Physicians, patients, and caregivers perceived faster wound closure. Adherence with therapy by patients was good, and patients expressed satisfaction with treatment and reported improvements in self-esteem, productivity, and social interaction. Oleogel-S10 was well tolerated; however, two patients reported worsening wounds related to gauze adherence. Two deaths during treatment interruption were reported and was not considered related to Oleogel-S10. This study supports the effectiveness of Oleogel-S10 in a real-world scenario in a country with scarce resources for the treatment of EB.
Subject(s)
Epidermolysis Bullosa Dystrophica , Epidermolysis Bullosa , Humans , Epidermolysis Bullosa Dystrophica/complications , Epidermolysis Bullosa Dystrophica/drug therapy , Quality of Life , Retrospective Studies , Wound Healing , Epidermolysis Bullosa/complications , Epidermolysis Bullosa/drug therapy , Organic ChemicalsABSTRACT
Red pitaya (Hylocereus costaricensis) is a promising species, with high cultivation potential due to the organoleptic and functional qualities of its fruits. However, irrigation water salinity can affect the crop yield. Therefore, materials rich in organic substances can minimize the damage caused by excess salts in soil and/or water. Thus, the objective of this study was to evaluate the influence of organic matter sources as attenuators of salt stress on the production and biochemical responses of red pitaya seedlings. A completely randomized design in 4 × 5 factorial scheme, with five sources of organic matter (humus, sheep manure, biofertilizer, organic compost and sand + soil) and four salinities (0.6, 2.6, 4.6 and 6.6 dS m-1) with four replicates and two plants per plot was used. The shoot length, root length, cladode diameter, number of cladodes, number of sprotus, root volume, shoot dry mass, root dry mass and total dry mass, root and shoot dry mass ratio, chlorophyll a, b and total, amino acids and soluble sugars were evaluated at 120 days after the treatments began to be applied. Red pitaya is moderately tolerant to salinity (ECw from 4.0 to 6.0 dS m-1). Organic compost and sheep manure attenuate the harmful effects of salinity on red pitaya seedlings. Under salt stress conditions, red pitaya plants increase their levels of proline, amino acids and total sugars.
A pitaia vermelha (Hylocereus costaricensis) é uma promissora espécie, com elevado potencial de cultivo devido às qualidades organolépticas e funcionais de seus frutos. Entretanto, a salinidade da água de irrigação pode afetar o rendimento produtivo da cultura. Diante disso, materiais ricos em substâncias orgânicas podem minimizar os danos provocados pelo excesso de sais no solo e/ou na água. Assim, o objetivo deste trabalho foi avaliar a influência de fontes de matéria orgânica como atenuante do estresse salino na produção e respostas bioquímicas de mudas de pitaia vermelha. O delineamento inteiramente casualizado em esquema fatorial 4 × 5, com cinco fontes de matéria orgânica (húmus, esterco ovino, biofertilizante, composto orgânico e areia + solo) e quatro salinidade (0.6, 2.6, 4.6 e 6.6 dS m-1), com quatro repetições e duas plantas por vaso foi utilizado. O comprimento da parte aérea, comprimento da raiz, diâmetro do cladódio, número de cladódios, número de brotos, volume da raiz, massa seca da parte aérea, massa seca da raiz e massa seca total, razão da massa seca da raiz e da parte aérea, clorofila a, b e total, aminoácidos e os açúcares solúveis foram avaliados aos 120 dias após o início da aplicação dos tratamentos. A pitaia vermelha é moderadamente tolerante a salinidade. O composto orgânico e estrume ovino atenuam os efeitos nocivos da salinidade nas mudas de pitaia vermelha. Sob condições de estresse salino, as plantas aumentam os níveis de aminoácidos e açúcares totais.
Subject(s)
Organic Chemicals , Cactaceae/growth & development , Cactaceae/metabolism , Fertilizers , Salt StressABSTRACT
In the context of a rising global temperature, biomass burning represents an increasing risk to human health, due to emissions of highly toxic substances such as polycyclic aromatic hydrocarbon (PAHs). Size-segregated particulate matter (PM) was collected in a region within the sugarcane belt of São Paulo state (Brazil), where biomass burning is still frequent, despite the phasing out of manual harvesting preceded by fire. The median of the total concentration of the 15 PAHs determined was 2.3 ± 1.8 ng m-3 (n = 19), where 63% of this content was in PM1.0. Concentrations of OPAHs and NPAHs were about an order of magnitude lower. PM2.5 collected in the dry season, when most of the fires occur, presented PAHs and OPAHs total concentrations three times higher than in the wet season, showing positive correlations with fire foci number and levoglucosan (a biomass burning marker). These results, added to the fact that biomass burning explained 65% of the data variance (PCA analysis), evidenced the importance of this practice as a source of PAHs and OPAHs to the regional atmosphere. Conversely, NPAHs appeared to be mainly derived from diesel-powered vehicles. The B[a]P equivalent concentration was estimated to be 4 times higher in the dry season than in the wet season, and was greatly increased during a local fire event. Cytotoxicity and genotoxicity of PM1.0 organic extracts were assessed using in vitro tests with human liver HepG2 cells. For both types of tests, significant toxicity was only observed for samples collected during the dry season. Persistent DNA damage that may have impaired the DNA repair system was also observed. The results indicated that there was a health risk associated with the air particulate mixture, mainly related to biomass burning, demonstrating the urgent need for better remediation actions to prevent the occurrence of burning events.
Subject(s)
Air Pollutants , Polycyclic Aromatic Hydrocarbons , Polycyclic Compounds , Humans , Particulate Matter/toxicity , Particulate Matter/analysis , Air Pollutants/toxicity , Air Pollutants/analysis , Polycyclic Compounds/analysis , Brazil , Biomass , Biodiversity , Environmental Monitoring , Temperature , Polycyclic Aromatic Hydrocarbons/toxicity , Polycyclic Aromatic Hydrocarbons/analysis , Organic Chemicals/analysis , SeasonsABSTRACT
In this work, we study the use of three configurations of an autoencoder neural network to process organic substances with the aim of generating meaningful molecular descriptors that can be employed to develop property prediction models. A total of 18,322,500 compounds represented as SMILES strings were used to train the model, demonstrating that a latent space of 24 units is able to adequately reconstruct the data. After AE training, an analysis of the latent space properties in terms of compound similarity was carried out, indicating that this space possesses desired properties for the potential development of models for forecasting physical properties of organic compounds. As a final step, a QSPR model was developed to predict the boiling point of chemical substances based on the AE descriptors. 5276 substances were used for the regression task, and the predictive ability was compared with models available in the literature evaluated on the same database. The final AE model has an overall error of 1.40% (1.39% with augmented SMILES) in the prediction of the boiling temperature, while other models have errors between 2.0 and 3.2%. This shows that the SMILES representation is comparable and even outperforms the state-of-the-art representations widely used in the literature.
Subject(s)
Organic Chemicals , Quantitative Structure-Activity Relationship , Organic Chemicals/chemistry , Neural Networks, Computer , Transition Temperature , TemperatureABSTRACT
We show that epilithic biofilms are a relevant nitrogen (N) source in a rocky mountain range in Brazil. During different seasons, we quantified nitrate, ammonium, dissolved organic N (DON) and total dissolved N (TDN) leached by a simulated short rain event. We quantified the epilithic autotrophic biomass by taxonomic groups and its correlation with leached N. We hypothesized that leached N would be correlated to heterocystous cyanobacteria biomass since they are more efficient N2 fixers. We estimated a landscape N supply of 8.5 kg.ha-1 .year-1 considering the mean precipitation in the region. TDN in leachate was mainly composed of DON (83.8% ± 22%), followed by nitrate (12.1% ± 3%) and ammonium (5% ± 5%). The autotrophic epilithic community was mainly composed of non-heterocystous (Gloeocapsopsis) and heterocystous cyanobacteria (Scytonema and Stigonema), except for a site more commonly affected by fire events that showed a dominance of Chlorophyta. Biogeochemical upscaling was facilitated by the fact that N leaching was not different among sites or related to autotrophic epilithic biomass or assemblage composition. In conclusion, the capacity of epilithic biofilms to provide N to surrounding systems is an ecosystem service that underscores the necessity to conserve them and their habitats.
Subject(s)
Ammonium Compounds , Cyanobacteria , Nitrogen , Ecosystem , Nitrates , Organic Chemicals , BiofilmsABSTRACT
To aid the possible prevention of multidrug resistance in tumors and cause lower toxicity, a set of sixteen novel dihydropyridine carboxylic acids derivatives 3a-p were produced; thus, the activation of various ynones with triflic anhydride was performed, involving a nucleophilic addition of several bis(trimethylsilyl) ketene acetals, achieving good yields requiring easy workup. The target molecules were unequivocally characterized by common spectroscopic methods. In addition, two of the tested compounds (3a, and 3b) were selected to perform in silico studies due to the highest cytotoxic activity towards the HCT-15 cell line (7.94 ± 1.6 µM and 9.24 ± 0.9 µM, respectively). Employing theoretical calculations with density functional theory (DFT) using the B3LYP/6-311++G(d,p) showed that the molecular parameters correlate adequately with the experimental results. In contrast, predictions employing Osiris Property Explorer showed that compounds 3a and 3b present physicochemical characteristics that would likely make it an orally active drug. Moreover, the performance of Docking studies with proteins related to the apoptosis pathway allowed a proposal of which compounds could interact with PARP-1 protein. Pondering the obtained results (synthesis, in silico, and cytotoxic activity) of the target compounds, they can be judged as suitable antineoplastic agent candidates.
Subject(s)
Antineoplastic Agents , Dihydropyridines , Neoplasms , Humans , Cell Line , Antineoplastic Agents/chemistry , Organic Chemicals , Carboxylic Acids/pharmacology , Dihydropyridines/pharmacology , Molecular Docking Simulation , Structure-Activity Relationship , Molecular StructureABSTRACT
Nitrate contamination in groundwater poses a significant threat to water quality and public health, especially in regions with limited data availability. This study addresses this challenge by employing machine learning (ML) techniques to predict nitrate (NO3--N) concentrations in Mexico's groundwater. Four ML algorithms-Extreme Gradient Boosting (XGB), Boosted Regression Trees (BRT), Random Forest (RF), and Support Vector Machines (SVM)-were executed to model NO3--N concentrations across the country. Despite data limitations, the ML models achieved robust predictive performances. XGB and BRT algorithms demonstrated superior accuracy (0.80 and 0.78, respectively). Notably, this was achieved using â¼10 times less information than previous large-scale assessments. The novelty lies in the first-ever implementation of the 'Support Points-based Split Approach' during data pre-processing. The models considered initially 68 covariates and identified 13-19 significant predictors of NO3--N concentration spanning from climate, geomorphology, soil, hydrogeology, and human factors. Rainfall, elevation, and slope emerged as key predictors. A validation incorporated nationwide waste disposal sites, yielding an encouraging correlation. Spatial risk mapping unveiled significant pollution hotspots across Mexico. Regions with elevated NO3--N concentrations (>10 mg/L) were identified, particularly in the north-central and northeast parts of the country, associated with agricultural and industrial activities. Approximately 21 million people, accounting for 10 % of Mexico's population, are potentially exposed to elevated NO3--N levels in groundwater. Moreover, the NO3--N hotspots align with reported NO3--N health implications such as gastric and colorectal cancer. This study not only demonstrates the potential of ML in data-scarce regions but also offers actionable insights for policy and management strategies. Our research underscores the urgency of implementing sustainable agricultural practices and comprehensive domestic waste management measures to mitigate NO3--N contamination. Moreover, it advocates for the establishment of effective policies based on real-time monitoring and collaboration among stakeholders.
Subject(s)
Groundwater , Water Pollutants, Chemical , Humans , Nitrates/analysis , Water Pollutants, Chemical/analysis , Environmental Monitoring/methods , Organic Chemicals , Water Quality , Water SupplyABSTRACT
Listeria monocytogenes is an important pathogen that has been implicated in foodborne illness. The aim of the present study was to investigate the diversity of virulence factors associated with the mechanisms of pathogenicity, persistence, and formation of biofilm L. monocytogenes by tandem analysis of whole-genome sequencing. The lineages that presented L. monocytogenes (LmAV-2, LmAV-3, and LmAV-6) from Hass avocados were lineages I and II. Listeria pathogenicity island 1 (LIPI-1) and LIPI-2 were found in the isolates, while LIPI-3 and Listeria genomic island (LGI-2) only was in IIb. Stress survival island (SSI-1) was identified in lineage I and II. In the in silico analysis, resistance genes belonging to several groups of antibiotics were detected, but the bcrABC and transposon Tn6188 related to resistance to quaternary ammonium salts (QACs) were not detected in L. monocytogenes. Subsequently, the anti-L. monocytogenes planktonic cell effect showed for QACs (MIC = 6.25 ppm/MBC = 100 ppm), lactic acid (MBC = 1 mg/mL), citric acid (MBC = 0.5 mg/mL) and gallic acid (MBC = 2 mg/mL). The anti-biofilm effect with organic acids (22 °C) caused a reduction of 4-5 log10 cfu/cm2 after 10 min against control biofilm L. monocytogenes formed on PP than SS. This study is an important contribution to understanding the genomic diversity and epidemiology of L. monocytogenes to establish a control measure to reduce the impact on the environment and the consumer.
Subject(s)
Listeria monocytogenes , Listeria , Listeria monocytogenes/genetics , Genomics , Lactic Acid , Anti-Bacterial Agents/pharmacology , Organic ChemicalsABSTRACT
The study addresses the application of the supercritical water technology in the simultaneous recycling of obsolete solar panels and treatment of persistent organic compounds. The obsolete solar panels samples were characterized by TEM-EDS, SEM, TG-DTA, XRD, WDXRF, MP-AES and elemental analysis. Initially, the optimized parameters for the degradation of solid organic polymers present in residual solar panels via oxidation in supercritical water were defined by an experimental design. Under optimized conditions, 550 °C, reaction time of 60 min, volumetric flow rate of 10 mL min-1 and hydrogen peroxide as oxidant agent, real laboratory liquid wastewater was used as feed solution to achieve 99.6% of polymers degradation. After the reaction, the solid product free of organic matter was recovered and characterized. On average, a metal recovery efficiency of 76% was observed. Metals such as aluminum, magnesium, copper, and silver, that make up most of the metallic fraction, were identified. Only H2, N2 and CO2 were observed in the gaseous fraction. Then, initial data on the treatment of the liquid decomposition by-products, generated during ScW processing, were reported. A total organic carbon reduction of 99.9% was achieved after the subsequential treatment via supercritical water oxidation using the same experimental apparatus. Finally, insights on the scale-up, energy integration and implementation costs of a ScW solid processing industrial unit were presented using the Aspen Plus V9 software.
Subject(s)
Copper , Water , Wastewater , Organic Chemicals , Recycling , Polymers , MagnesiumABSTRACT
Nanosensors work on the "Nano" scale. "Nano" is a unit of measurement around 10- 9 m. A nanosensor is a device capable of carrying data and information about the behavior and characteristics of particles at the nanoscale level to the macroscopic level. Nanosensors can be used to detect chemical or mechanical information such as the presence of chemical species and nanoparticles or monitor physical parameters such as temperature on the nanoscale. Nanosensors are emerging as promising tools for applications in agriculture. They offer an enormous upgrade in selectivity, speed, and sensitivity compared to traditional chemical and biological methods. Nanosensors can be used for the determination of microbe and contaminants. With the advancement of science in the world and the advent of electronic equipment and the great changes that have taken place in recent decades, the need to build more accurate, smaller and more capable sensors was felt. Today, high-sensitivity sensors are used that are sensitive to small amounts of gas, heat, or radiation. Increasing the sensitivity, efficiency and accuracy of these sensors requires the discovery of new materials and tools. Nano sensors are nanometer-sized sensors that, due to their small size and nanometer size, have such high accuracy and responsiveness that they react even to the presence of several atoms of a gas. Nano sensors are inherently smaller and more sensitive than other sensors.
Subject(s)
Nanoparticles , Organic Chemicals , AgricultureABSTRACT
Ion mobility mass spectrometry (IM-MS) techniques have become highly valued as a tool for structural characterization of biomolecular systems since they yield accurate measurements of the rotationally averaged collision cross-section (CCS) against a buffer gas. Despite its enormous potential, IM-MS data interpretation is often challenging due to the conformational isomerism of metabolites, lipids, proteins, and other biomolecules in the gas phase. Therefore, reliable and fast CCS calculations are needed to help interpret IM-MS data. In this work, we present MassCCS, a parallelized open-source code for computing CCS of molecules ranging from small organic compounds to massive protein assemblies at the trajectory method level of description using atomic and molecular buffer gas particles. The performance of the code is comparable to other available software for small molecules and proteins but is significantly faster for larger macromolecular assemblies. We performed extensive tests regarding accuracy, performance, and scalability with system size and number of CPU cores. MassCCS has proven highly accurate and efficient, with execution times under a few minutes, even for large (84.87 MDa) virus capsid assemblies with very modest computational resources. MassCCS is freely available at https://github.com/cces-cepid/massccs.
Subject(s)
Proteins , Software , Mass Spectrometry/methods , Proteins/chemistry , Organic ChemicalsABSTRACT
A product study was performed for the reaction of γ-caprolactone (GCL) and γ-heptalactone (GHL) initiated by OH radicals at (298 ± 2) K and atmospheric pressure, in presence of NOx. The identification and quantification of the products were performed in a glass reactor coupled with in situ FT-IR spectroscopy. The following products were identified and quantified with the corresponding formation yields (in %) for the OH + GCL reaction: peroxy propionyl nitrate (PPN) (52 ± 3), peroxy acetyl nitrate (PAN) (25 ± 1), and succinic anhydride (48 ± 2). For the GHL + OH reaction, the products detected with their corresponding formation yields (in %) were the following: peroxy n-butyryl nitrate (PnBN) (56 ± 2), peroxy propionyl nitrate (PPN) (30 ± 1) and succinic anhydride and (35 ± 1). Upon these results, an oxidation mechanism is postulated for the title reactions. The positions with the highest H-abstraction probabilities for both lactones are analyzed. Specifically, the increased reactivity of the C5 site, as indicated by structure reactivity estimations (SAR), is suggested by the identified products. For both GCL and GHL degradation appears to follow degradation paths including ring preservation and opening. The atmospheric implications of the APN formation as a photochemical pollutant and as NOx reservoirs of species is assessed.
Subject(s)
Hydroxyl Radical , Succinic Anhydrides , Spectroscopy, Fourier Transform Infrared , Hydroxyl Radical/chemistry , Nitrates , Atmospheric Pressure , Lactones , Organic ChemicalsABSTRACT
Mangrove sediments are known to be potentially active reducing zones for nitrogen removal. The goal of this work was to investigate the potential for nitrate reduction in marine mangrove sediments along a canal impacted by anthropogenic activity (Guadeloupe, Lesser Antilles). To this end, the effect of nitrate concentration, organic carbon load, and hydraulic retention time was assessed as factors affecting these nitrate reduction rates. Nitrate reduction potential was determined using flow-through reactors in marine mangrove sediments collected along "The Canal des Rotours" in Guadeloupe. Potential nitrate reduction rates, in the presence of indigenous organic carbon, generally increased upon increasing nitrate supply from around 120 nmol cm-3 h-1 (low nitrate) up to 378 nmol cm-3 h-1 (high nitrate). The potential for nitrate reduction increased significantly with the addition of mangrove leaves, whereas the addition of simple, easily degradable carbon (acetate) resulted in an almost fivefold increase in nitrate reduction rates (up to 748 nmol cm-3 h-1 ). The hydraulic retention time also had an impact on the nitrate reducing capacity due to an increased contact time between nitrate and the benthic microbial community. Marine mangrove sediments have a high potential to mitigate nitrogen pollution, mainly governed by the presence of large amounts of degradable carbon in the form of litter. The mangrove sediments from this Caribbean island, currently exposed to a small tidal effect, could increase their nitrate elimination capacities due to prolonged water retention via engineering.